Metamath Proof Explorer


Theorem dvgrat

Description: Ratio test for divergence of a complex infinite series. See e.g. remark "if ( abs( ( a( n + 1 ) ) / ( an ) ) ) >_ 1 for all large n..." in https://en.wikipedia.org/wiki/Ratio_test#The_test . (Contributed by Steve Rodriguez, 28-Feb-2020)

Ref Expression
Hypotheses dvgrat.z Z=M
dvgrat.w W=N
dvgrat.n φNZ
dvgrat.f φFV
dvgrat.c φkZFk
dvgrat.n0 φkWFk0
dvgrat.le φkWFkFk+1
Assertion dvgrat φseqM+Fdom

Proof

Step Hyp Ref Expression
1 dvgrat.z Z=M
2 dvgrat.w W=N
3 dvgrat.n φNZ
4 dvgrat.f φFV
5 dvgrat.c φkZFk
6 dvgrat.n0 φkWFk0
7 dvgrat.le φkWFkFk+1
8 3 1 eleqtrdi φNM
9 eluzelz NMN
10 8 9 syl φN
11 uzid NNN
12 11 2 eleqtrrdi NNW
13 10 12 syl φNW
14 simpr φk=Nk=N
15 14 eleq1d φk=NkWNW
16 14 fveq2d φk=NFk=FN
17 16 fveq2d φk=NFk=FN
18 17 breq2d φk=N0<Fk0<FN
19 15 18 imbi12d φk=NkW0<FkNW0<FN
20 2 eleq2i kWkN
21 1 uztrn2 NZkNkZ
22 20 21 sylan2b NZkWkZ
23 3 22 sylan φkWkZ
24 23 5 syldan φkWFk
25 absgt0 FkFk00<Fk
26 24 25 syl φkWFk00<Fk
27 6 26 mpbid φkW0<Fk
28 27 ex φkW0<Fk
29 3 19 28 vtocld φNW0<FN
30 13 29 mpd φ0<FN
31 0red φ0
32 14 eleq1d φk=NkZNZ
33 16 eleq1d φk=NFkFN
34 32 33 imbi12d φk=NkZFkNZFN
35 5 ex φkZFk
36 3 34 35 vtocld φNZFN
37 3 36 mpd φFN
38 37 abscld φFN
39 31 38 ltnled φ0<FN¬FN0
40 30 39 mpbid φ¬FN0
41 10 adantr φF0N
42 38 adantr φF0FN
43 simpr φF0F0
44 2 fvexi WV
45 44 mptex iWFiV
46 45 a1i φF0iWFiV
47 24 adantlr φF0kWFk
48 eqidd φF0kWiWFi=iWFi
49 simpr φF0kWi=ki=k
50 49 fveq2d φF0kWi=kFi=Fk
51 50 fveq2d φF0kWi=kFi=Fk
52 simpr φF0kWkW
53 fvex FkV
54 53 a1i φF0kWFkV
55 48 51 52 54 fvmptd φF0kWiWFik=Fk
56 2 43 46 41 47 55 climabs φF0iWFi0
57 abs0 0=0
58 56 57 breqtrdi φF0iWFi0
59 47 abscld φF0kWFk
60 55 59 eqeltrd φF0kWiWFik
61 2fveq3 i=NFi=FN
62 61 breq2d i=NFNFiFNFN
63 62 imbi2d i=NφFNFiφFNFN
64 2fveq3 i=kFi=Fk
65 64 breq2d i=kFNFiFNFk
66 65 imbi2d i=kφFNFiφFNFk
67 2fveq3 i=k+1Fi=Fk+1
68 67 breq2d i=k+1FNFiFNFk+1
69 68 imbi2d i=k+1φFNFiφFNFk+1
70 38 adantr φNFN
71 70 leidd φNFNFN
72 71 expcom NφFNFN
73 38 ad2antrr φkWFNFkFN
74 24 adantr φkWFNFkFk
75 74 abscld φkWFNFkFk
76 2 peano2uzs kWk+1W
77 ovex k+1V
78 eleq1 i=k+1iWk+1W
79 78 anbi2d i=k+1φiWφk+1W
80 fveq2 i=k+1Fi=Fk+1
81 80 eleq1d i=k+1FiFk+1
82 79 81 imbi12d i=k+1φiWFiφk+1WFk+1
83 eleq1 k=ikWiW
84 83 anbi2d k=iφkWφiW
85 fveq2 k=iFk=Fi
86 85 eleq1d k=iFkFi
87 84 86 imbi12d k=iφkWFkφiWFi
88 87 24 chvarvv φiWFi
89 77 82 88 vtocl φk+1WFk+1
90 76 89 sylan2 φkWFk+1
91 90 adantr φkWFNFkFk+1
92 91 abscld φkWFNFkFk+1
93 simpr φkWFNFkFNFk
94 7 adantr φkWFNFkFkFk+1
95 73 75 92 93 94 letrd φkWFNFkFNFk+1
96 95 ex φkWFNFkFNFk+1
97 20 96 sylan2br φkNFNFkFNFk+1
98 97 expcom kNφFNFkFNFk+1
99 98 a2d kNφFNFkφFNFk+1
100 63 66 69 66 72 99 uzind4 kNφFNFk
101 100 impcom φkNFNFk
102 20 101 sylan2b φkWFNFk
103 102 adantlr φF0kWFNFk
104 103 55 breqtrrd φF0kWFNiWFik
105 2 41 42 58 60 104 climlec2 φF0FN0
106 40 105 mtand φ¬F0
107 eluzel2 NMM
108 8 107 syl φM
109 108 adantr φseqM+FdomM
110 4 adantr φseqM+FdomFV
111 simpr φseqM+FdomseqM+Fdom
112 5 adantlr φseqM+FdomkZFk
113 1 109 110 111 112 serf0 φseqM+FdomF0
114 106 113 mtand φ¬seqM+Fdom
115 df-nel seqM+Fdom¬seqM+Fdom
116 114 115 sylibr φseqM+Fdom